LinkedIn Corp. signage is displayed on the facade of the company's headquarters in California. (Photographer: David Paul Morris/Bloomberg)

LinkedIn Corp. signage is displayed on the facade of the company's...

References have posed a corporate conundrum for decades.

Worried about defamation lawsuits, many companies refuse to allow their managers to discuss the work performance of former employees. Many companies won't comment at all; others will confirm dates of employment and whether the former employees are eligible for re-hire.

That's all changing with the popularity of social media, which depend upon networking. And one of the best ways to make a connection on Linked-In? Make a recommendation.

Every day, people get on LinkedIn, Twitter, Facebook and other social media sites to tout the skills of their co-workers, subordinates, managers and competitors.

But sometimes those comments come back to haunt them, especially when the person they recommended as a brilliant professional or gung-ho employee was terminated for poor performance and is sitting across the deposition table.

It happens a lot, he said, recalling the times when his clients were fired for allegedly poor performance, yet former executives, managers and co-workers had praised the same workers' skills on LinkedIn.

Ahmad doesn't always score legal points by noting the disparity. But it makes the other side look a little silly.

'Hilarious as all get out'

"It's just as hilarious as all get out," he said.

In once case, Ahmad said, his client had once worked with the opposing lawyer. In glowing language, the lawyer had written a LinkedIn recommendation on how wonderful it was to work together.

It clearly had been a way to gain favor, Ahmad said. But those comments were hard to explain away once the same lawyer was on the other side of the case and representing the company that used to employ the executive.

Bill Bradshaw, president of Simplified Sales Strategies, a sales consulting company that works with small and midsize companies to boost sales revenues, is like a lot of executives. He didn't think twice about the online recommendations that everyone seems to make on LinkedIn.

Nor has the former human resource executive - one of the founders of the Achilles Group, which provides outsourced personnel services - ever talked to a single business owner who was concerned about employees recommending vendors, clients and co-workers.

Until now. He wants to know what would happen if a salesperson recommended a different vendor than the company's approved vendor.

He suspects many executives and senior managers who aren't aware of LinkedIn aren't aware of the pitfalls either.

Martin Shellist, an employment lawyer who represents mostly individuals with Shellist Lazarz & Slobin, is well aware of the danger. But he also realizes why it's so common.

When he signs on to LinkedIn, a list of suggestions of people to endorse pops up. People click without really knowing what they're clicking.

Many don't stop and think that they are providing an actual endorsement, said Bill Bux, an employment lawyer with Locke Lord who represents management. To avoid anything coming back to haunt him, Bux limits his comments to face-to-face conversations, he said.

Trade secrets

Another pitfall is that LinkedIn recommendations can be so specific that they inadvertently give away trade secrets, Ahmad said. For example, he said, a company may try to argue that an ex-employee took advantage of confidential information in trying to win business with former customers.

That can be difficult to prove, Ahmad said, when the vendor had already posted a LinkedIn recommendation to the effect of: "We needed this type of drilling fluid for this type of corrosive environment, and he came up with the solution."